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Beauveria (Hyphomycetes) Found in plant debris and soil. Some
species are well known parasites of insects. It is also isolated
from food materials and indoor environments.
Bipolaris (Hyphomycetes)
A common saprobe and plant pathogen frequently isolated from plant
debris and soil. It is also a common cause of leaf spot on golf
course turf. A few species are capable of causing disease in humans.
Botrytis (Hyphomycetes)
Teleomorph: Sclerotinia (Ascomycetes) Most species are important
plant pathogens, such as B. cinerea, which can cause gray mold
disease on various plant parts. Can be found in food and indoor
environment, particularly on plants, fruits, and vegetables.
Cercospora (Hyphomycetes)
Teleomorph: Mycosphaerellaceae Widespread plant pathogens that cause
leaf spot on many plants.
Chaetomium (Ascomycetes)
A common fungus in soils, dung, decaying organic matter, seeds, and
wood or other cellulose-containing materials. Can be found indoors
in water-damaged buildings on sheet rock, wallpaper, and other paper
products. It is a common cause of food spoilage. Some species are
allergenic but rarely cause human infections.
Chromelosporium
Teleomorph: Peziza (Ascomycetes)
Chrysonilia (Hyphomycetes)
Teleomorph: Neurospora (Ascomycetes) This genus is widespread; being
found in food and indoors. Chrysonilia sitophila is popularly
referred to as the red bread mold that occurs on breads, baked
goods, meat, and fruits.
Chrysosporium (Hyphomycetes)
Teleomorph: Various Ascomycetes A common soil saprobe occasionally
isolated from human or animal skin and nail. Chrysosporium inops is
xerophilic and occurs in food.
Cladosporium (Hyphomycetes)
Teleomorph: Mycosphaerella (Ascomycetes) Widely distributed as plant
pathogens and saprobes. It is the most frequently found fungus in
outdoor air. Indoors, it usually occurs at low concentrations in
damp or humid areas, but may be found in high concentrations in
water-damaged building materials. Its ability to sporulate heavily
and to get airborne makes it an important fungal allergen.
Frequently isolated as a contaminant in foods. Only occasionally
associated with disease in humans; one species can cause chronic
subcutaneous infection.
Coelomycetes
An artificial class of fungi characterized by asexual spores that
are produced within a cavity lined by fungal tissue or fungal and
host tissues. Most are saprobes or pathogens on plants, fungi, and
lichens.
Coprinus (Basidiomycetes)
These mushrooms are popularly referred to as the inky caps because
their gills dissolve into a black inky fluid at maturity. Found on
wood, dung, humus, and soil. Some species are edible.
Curvularia (Hyphomycetes)
Teleomorph: Cochliobolus (Ascomycetes) A common saprobe found in
soil, plants, cereals, and cellulosic materials such as paper and
archives. Some species are plant pathogens but can also occur
indoors. It is allergenic and may cause infections in
immunocompromised people.
Dicyma (Hyphomycetes)
Teleomorph: Ascotricha (Ascomycetes)
Doratomyces
A saprobe commonly found on decaying plant materials, straw, dung,
wood, and in soil. It produces dark, sooty colonies. It has the
ability to penetrate cellophane and to decompose cellulose.
Doratomyces stemonitis is suspected to be the causal agent of "speck
rot" on potatoes.
Dreschlera (Hyphomycetes)
Mostly plant pathogens that cause leaf spot, seedling blight, leaf
stripe, or net blotch.
Emericella (Ascomycetes)
Anamorph: Aspergillus (Hyphomycetes) Usually found in soil,
potatoes, grain, citrus, and stored seeds. Can be found in food and
the indoor environment. Emericella nidulans can produce a
sterigmatocystin mycotoxin and can be pathogenic to man and animals.
Epicoccum (Hyphomycetes)
A cosmopolitan saprobe isolated from air, soil, grain, seeds,
textiles, paper products, and food materials. Can be a plant
pathogen, and is a common cause of leaf spots of various plants. Can
be found in indoor environments, where it can grow under conditions
of low humidity. It is a known allergen, and is occasionally
isolated from human skin and sputum.
Eurotium (Ascomycetes)
Anamorph: Aspergillus (Hyphomycetes) Can be found in stored food,
fruit juices, grains, nuts, milled rice, spices, meat products, and
peas. Also commonly occurs in indoor environments. Eurotium
herbariorum may cause keratitis and indigestion in man.
Exophiala (Hyphomycetes)
Widely distributed as a saprobe in soil, water, on plants and
decaying wood. It is an occasional contaminant of feet and nails.
Exophiala infections have also been reported in animals, including
fish.
Fusarium (Hyphomycetes)
Soil-borne fungi containing many plant pathogens that cause root
rot, stem rot, fruit rot, and vascular wilt. Common on commodities,
such as rice, bean, soybean, and other crops. Some species are
important mycotoxin producers, and others notably F. oxysporum, F.
solani and F. moniliforme, are recognized as opportunistic pathogens
of man and animals. The species that can produce three of the five
internationally regulated mycotoxins are:
Fusarium sp Habitat Trichothecenes Zearalenone Fumonisins F.
acuminatum Food Can produce - - F. crookwellense Food Can produce
Can produce - F. culmorum Food, Indoor Can produce Can produce - F.
equiseti Food Can produce Can produce - F. graminearum Food Can
produce Can produce - F. poae Food Can produce - - F. proliferatum
Food - - Can produce F. sambucinum Food Can produce - - F.
semitectum Food - Can produce - F. sporotrichioides Food, Indoor Can
produce - - F. verticillioides Food - - Can produce
Ganoderma (Basidiomycetes)
Large, very hard, woody bracket fungi that grow on living and dead
trees. Some species are common on oaks, chestnuts, and conifers such
as hemlock, spruce, and pine. Many species are being investigated
for possible medicinal uses.
Geotrichum (Ascomycetes Yeast)
Teleomorph Dipodascus, Galactomyces (Ascomycetes) Commonly found in
soil, water, air, decaying leaves, rotting paper, and textiles.
Involved in spoilage of food like bakery products, dairy products,
juices, fruits, and vegetables. Can be found in indoor environments
with some species producing strong odors.
Hyphomycetes
A group of fungi in which asexual spores called conidia are produced
from special conidiogenous cells.
Helvella (Ascomycetes)
A saddle-shaped fruiting body of a fungus found on soil, or
sometimes on rotting wood. Occasionally found growing on soil under
houses.
Memnoniella (Hyphomycetes)
Mainly isolated from soils and dead plant material in tropical
countries but has also been isolated from indoor sources such as
paper, wallpaper, and textiles. Exposure to this genus should be
avoided as they can produce griseofulvins, a potentially toxic
metabolite. Emerging research has proposed that Memnoniella species
actually belong to Stachybotrys.
Monodictys (Hyphomycetes)
Found on dead wood, stem, tree bark, damp linoleum, and paper.
Isolated from soil and air.
Myxomycetes
Popularly called slime molds. These are not true fungi
taxonomically. Some species are found in the soil, in decaying wood,
or other organic matter, where they produce structures full of
powdery resting spores.
Mucor (Zygomycetes)
Often found in soil, plants, hay, stored seeds, and manure. They can
be found indoors in house dust, HVAC system dust, and poorly
maintained carpets. They are rapid growers and can contaminate many
kinds of stored food, including fruits and vegetables. A few species
have been recovered from well-documented cases of zygomycosis. In
general, infections due to members of this genus are rare.
Nigrospora (Hyphomycetes)
Some species are common on plants, particularly in the tropics.
Occasionally isolated from soil, air, and foodstuffs.
Paecilomyces (Hyphomycetes)
Teleomorph: Byssochlamys (Ascomycetes) A common saprobe found on
dead plants and compost. Some species are insect parasites while
others cause food spoilage. It is rarely a human pathogen but can
cause infection in animals. However, some species, such as P.
variotii, P. marquandii and P. lilacinus are emerging as causative
agents of disease in immunocompromised individuals.
Penicillium (Hyphomycetes)
Many species are common contaminants on a variety of substrates. May
be found indoors in air samples, carpet dust, or on wallpaper. Some
species are able to produce mycotoxins, as summarized below. Human
pathogenic species are rare, only limited to P. marneffei, which
causes disease in immunocompromised individuals. Some species are
used for commercial production, such as P. chrysogenum for the
antibiotic penicillin, P. griseofulvum for the antibiotic
griseofulvin, and P. roquefortii for blue cheese.
Penicillium Habitat Toxic Metabolite P. aurantiogriseum Food, Indoor
Can produce P. brevicompactum Food, Indoor - P. chrysogenum Food,
Indoor - P. citrinum Food, (Indoor) Can produce P. commune Food,
Indoor Can produce P. corylophilum Food, Indoor - P. crustosum Food
Can produce P. digitatum Food - P. expansum Food Can produce P.
funiculosum Food, Indoor - P. griseofulvum Food - P. olsonii Food,
Indoor - P. oxalicum Food Can produce P. polonicum Food, Indoor Can
produce P. roqueforti Food - P. rugulosum Food, Indoor - P.
variabile Food, Indoor - P. verrucosum Food Can produce P.
viridicatum Food Can produce
Periconia (Hyphomycetes)
A widespread fungus commonly found on various substrates, including
stalks of grasses, herbaceous stems, dead leaves, or leaf spots. The
spores of Periconia species are often indistinguishable from the
spores of smut fungi like Ustilago species, when collected on air
cassettes. Both genera can have spores that are brown, verruculose,
or echinulate, ranging from 10-16 microns in diameter.
Peziza (Ascomycetes)
Anamorph: Chromelosporium Popularly referred to as cup fungi. They
vary in size and color, but are mostly shades of ocher or brown to
gray-violet. Most species are commonly found on old straw, compost,
peat, leaf litter, rotting wood, damp soil, and other moist
substrates. Can be found indoors in wet basements and wet carpets.
Phialophora (Hyphomycetes)
Teleomorph: Ascomycetes Occurs in nature as a soft rot fungus on
wood often causing a distinct blue stain. Can cause diseases in
immunocompromised individuals.
Phoma (Coelomycete)
Found in soil and plant materials as saprobes. Will grow on a
variety of materials such as butter, paint, cement, and rubber.
Occasionally pathogenic to plants and humans, but infection from
this fungus is extremely rare.
Pithomyces (Hyphomycetes)
This genus is common in soil and on dead or decaying plant
materials. Requires high moisture level for spore germination. Can
potentially produce cyclodepsipeptides, sporidesmolides, and
sporidesmin.
Rhinocladiella (Hyphomycetes)
Teleomorph: Capronia (Ascomycetes)
Rhizopus (Zygomycete)
Frequently isolated from soil and agricultural products, such as
cereals and vegetables. Can cause infection in immunocompromised,
malnourished or severely burned people.
Rhodotorula (Yeast)
A reddish yeast frequently isolated from air, soil, water, fruit
juice, dairy products, and other substrates. Typically found as a
saprobe in moist environments indoor such as carpeting, cooling
coils, water tanks, humidifiers, and drain pans. Reported to be
allergenic. Has been found to colonize terminally ill patients.
Rusts
Obligate parasitic fungi, which belong to Teliomycetes – Uredinales
that cause plant diseases.
Scopulariopsis (Hyphomycetes)
Teleomorph: Microascus (Ascomycetes) Mainly soil-borne, but also
frequently isolated from wood, grain, fruit, paper, and food such as
meat and dairy products. Also isolated from indoor environments.
Most species can liberate arsenic gaseous compounds that can lead to
arsenic poisoning. Has recently been associated with invasive human
infections.
Scytalidium (Hyphomycetes)
Isolated from wood and soil.
Serpula (Basidiomycete)
Wood-attacking fungi. Serpula lacrymans is popularly referred to as
the dry rot fungus or house fungus.
Smuts (Teliomycetes)
Obligate parasites and pathogens of plants that cause smut on
various plant parts such as Silene anthers, corn kernels, onion
bulbs, and rice grains.
Sordaria (Ascomycetes)
Common on dung. One species, S. fimicola is fairly common and is
found on other substrates besides dung.
Sporobolomyces (Yeast)
Can be commonly detected in air samples. Frequently encountered
indoors in water tanks, humidifiers, drain pans, etc.
Sporoschisma (Hyphomycetes)
Found on rotten wood and dead stems.
Sporothrix (Hyphomycetes)
Teleomorph: Ophiostoma (Ascomycetes) Isolated from soil, live or
dead plants, and peat moss. S. schenckii is an agent of human
sporotrichosis, cutaneous infection, and ocular mycosis, usually in
immunocompromised people.
Sporotrichum (Hyphomycetes)
Teleomorph: Phanerochaete (Basidiomycetes) Can get airborne and be
inhaled where it can form giant cells in the lungs.
Stachybotrys (Hyphomycetes)
A common saprophyte found on many substrates like grains, decaying
plant materials, textiles, and tobacco. Grows indoors on
water-damaged cellulose rich materials, such as sheet rock, paper,
ceiling tiles, insulation backing, gypsum board, and wallpaper. The
presence of this fungus can be significant due to its ability to
produce mycotoxins under certain environmental conditions. Exposure
to the toxins can occur through inhalation, ingestion, or skin
exposure.
It is possible that Stachybotrys may play a role in the development
of sick building syndrome, but probably only in conjunction with
other factors. Until more information is available on the health
risks of environmental exposure to Stachybotrys, caution should be
taken when dealing with this fungus.
Stemphylium (Hyphomycetes)
A common saprobe typically is found on dead plants and wood. It has
been also isolated from air, paper, and cellulosic materials.
Syncephalastrum (Zygomycete)
Often isolated from soil and dung in tropical and subtropical
regions. Can also be a persistent laboratory contaminant.
Taeniolella (Hyphomycetes)
Common on dead branches, wood, and senescent leaves. Was isolated
from human cutaneous and subcutaneous lesions.
Tetraploa (Hyphomycetes)
Teleomorph: Massarina (Ascomycetes) Found on stems and leaf bases of
many plants. Tetraploa aristata has been reported to cause keratitis.
Thermomyces (Hyphomycetes)
A thermophilic fungus that grows rapidly at 40° C.
Torula (Hyphomycetes)
Cosmopolitan fungi commonly found on wood, leaves, plant roots, and
plant litter. Has also been isolated from air and soil. Some species
cause stains in hardwoods.
Trichoderma (Hyphomycetes)
Very common especially in soil and decaying wood, dead leaves,
fallen timber, compost heaps, and activated sludge. Can be found
indoors in water-damaged buildings. Has occasionally been associated
with disease in immunocompromised individuals.
Trichophyton (Hyphomycetes)
Some species are dermatophytes (growing on the skin) of humans or
animals.
Tritirachium (Hyphomycetes)
A saprobe commonly isolated from decaying plant materials. Easily
gets airborne. Can cause corneal ulcers.
Ulocladium (Hyphomycetes)
Found as a saprobe in soil, plant materials, rotten wood, paper,
textiles and cellulose materials. Frequently collected in air and
dust samples. Can grow indoors on water-damaged building materials.
Has not been associated with disease in humans but can be very
allergenic.
Verticillium (Hyphomycetes)
Mostly soilborne, root-inhabiting fungi that cause vascular wilt and
other diseases on plants. Some species also infect mushrooms, rusts,
and other fungi, as well as nematodes, ticks, mites and other
insects. Other species can attack wool and textiles, or can
decompose paper.
Wallemia (Hyphomycetes)
A very xerophilic fungus that has been isolated from soil, air, hay,
textiles, and food such as jam, salted fish, and milk products. Can
cause allergies.
Yeast
A growth form exhibited by some fungi in which the fungus exists as
single budding cells.
Zygomycetes
A class of fungi where the asexual spores are mostly formed
endogenously in sporangia. The majority of the species are saprobes.
Definitions
Allergen/allergenic
An allergen is an antigen, principally a protein, which can elicit
symptoms of allergic disease in a previously sensitized individual.
This antigen is specifically recognized by the individual’s immune
system, with subsequent development of specific antibody and/or cell
mediated immunity. Fungi can elicit an allergic reaction ranging
from mild to severe, anywhere from a stuffy nose, through hay fever
and asthma to pneumonitis. In most cases, the physical condition of
the host, the amount of allergen the host is exposed to (spores,
fungal hyphae, dust, pollen, etc.) and the degree of sensitization
of the individual determines the severity of the reaction. In
general, common environmental or indoor air contaminating fungi most
often affect humans as irritants that elicit an immune response that
we generally associate with allergies (hypersensitivity).
Anamorph
The imperfect stage or asexual state of the fungus produced by
mitosis.
Colony
An individual fungal growth on an agar culture plate or
natural/manufactured substrate, when the fungus has grown
sufficiently to be readily seen with a hand lens or low-power
microscope.
Conidia (conidium, singular)
Asexual non-motile spores.
Conidiophore
The specialized hypha or cell on which conidia are produced.
Hyphae (singular hypha)
The individual filament or thread that make up a fungus.
Hyphal Fragment
A portion of the fungal mycelium that does not have any spores or
other diagnostic fungal structures, and therefore, could not be
identified.
Immunocompromised
Incapable of developing a normal immune response, usually as a
result of disease (lupus, HIV), malnutrition, or immunosuppressive
therapy (chemotherapy, corticosteroids).
Mycotoxin
Secondary metabolites produced by fungi, which are toxic to human
and animals in small quantities. Production of a specific mycotoxin
tends to be genus-, species-, or even strain-specific.
No Mold Detected
This result indicates that spores, hyphae, or any fungal structures
were not observed from the sample.
Parasite
An organism that requires a living host to survive. It lives in or
on the host and derives nutrients or other substances from the host.
It is generally not able to live saprophytically, and it may often
cause extensive damage to the host.
Pathogen
An organism that can cause a disease on another living organism.
Saprobe
A fungus that feeds by external digestion of dead organic matter,
and usually has the ability to adapt rapidly on the substrate.
Spore
An individual reproductive body or propagule of fungi, similar to a
seed of plant.
Spore-producing structures
Fungal parts involved in spore production such as hyphae,
conidiophores, phialides, and fruiting bodies, among others.
Teleomorph
The perfect stage or sexual state of the fungus involved in
producing meiotic or sexual spores.
Xerophilic
Able to grow under dry conditions.
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